Conventionally, a dispensing device used for dispensing a liquid sample containing an analyte or a regent performs dispensing, by operating a dispensing pump, to discharge a liquid within a tube, for example, to aspirate or discharge the liquid to aspirate a liquid sample from a dispensing nozzle connected to the tube to discharge the aspirated liquid sample to a predetermined position.
However when parts are exchanged for maintenance and the like, in some cases, slight bubbles are mixed into the tube and the bubbles adhere to inside of a cylinder for hosing a liquid or a surface of a plunger which regulates a compression/decompression pressure of the cylinder. In such case, dispensing a liquid sample in the condition where bubbles are adhered causes a variability in the amount of the liquid sample to be dispensed, thereby causing a problem of reducing a dispensing accuracy.
In order to solve this problem, a dispensing device is known that flows a liquid so as to pivot around a plunger in a direction from an injection port of the cylinder to a discharge port of the cylinder to generate a pivotal flow in the cylinder, and removes bubbles adhered inside the cylinder and on the surface of the plunger by the generated pivotal flow (Reference 1).    Reference 1: Japanese Laid-Open Publication No. 2006-343246